This study is designed to evaluate (1) the effect of thyrotropin suppression in nodular goiter and thyroid cancer, (2) factors influencing survivorship in patients with thyroid cancer, (3) improved diagnostic methods to distinguish between cancer and benign thyroid disease, and (4) to characterize qualitatively and quantitatively TSH receptors in normal and pathologic human thyroid tissue. BIBLIOGRAPHIC REFERENCES: Thomas, C.G., Jr., Buckwalter, J.A., Staab, E.V., and Kerr, C.Y.: Evaluation of Dominant Thyroid Masses. Annals of Surgery 183:413, 1976. Thomas, C.G., Jr. and Buckwalter, J.A.: Cancer of the Thyroid. Advances in Surgery, William Longmire, ed., Year Book Medical Publishers. 10:245, 1976.